The passage of the Affordable Care Act represents an important turning point for our health care system. The health industry is arguably one of the most, if not the most, powerful interest groups in Washington. That President Barack Obama and congressional leaders could negotiate such a comprehensive health reform package with so many vested interests involved is nothing short of a miracle.

The passage of the Affordable Care Act represents an important turning point for our health care system. The health industry is arguably one of the most, if not the most, powerful interest groups in Washington. That President Barack Obama and congressional leaders could negotiate such a comprehensive health reform package with so many vested interests involved is nothing short of a miracle.

We are nearly 18 months into implementation, and the health industry and many states have seized this opportunity and begun working on transforming our health system.

If Congress withholds the funding needed to fulfill the federal government's responsibilities under the ACA, it could seriously slow or stall the positive momentum we are starting to see. Such a decision would do nothing to heal our health care woes and could backfire and make a bad situation worse.

It may come as a surprise to some, but no one is entirely happy with the ACA. This may be the best thing about the law. To get the bill passed, every interest group had to give up something. The result: The ACA represents a complex and delicate patchwork of reforms that have the potential to restructure powerful, entrenched economic interests in ways that will improve access to health care for more Americans.

On the legal front, challenges to the law's individual mandate of health insurance coverage have produced contradictory court rulings, and it is nearly certain the Supreme Court will need to weigh in on this critical question. But it is less clear when the high court will offer a ruling or what the implications might be on the myriad reforms outlined in the law.

One thing is clear: The wheels of reform are moving, and picking up speed because of the passage of the ACA.

Some argue that Mitt Romney, as governor of Massachusetts, started this wave of reform, but the ACA has provided other states, ranging from California to Vermont, an opening to launch major initiatives to improve the accessibility and affordability of health insurance and to make other fundamental and long-overdue reforms.

The winds of change also are howling within the corridors of hospitals, health systems, and doctors' offices across the nation, as they are taking important steps to redesign care delivery systems to be more accountable and cost-effective. Health insurers, medical device and pharmaceutical companies, and private enterprises also are responding with a wide array of products and services that will be essential in reducing the rising cost of care.

The success or failure of the ACA in improving the accessibility and quality of health care will depend, in large part, on the careful implementation of the remarkably intricate web of carefully negotiated changes across the public and private sectors. The federal government must do its part to develop regulations and make changes to programs, policies and practices to support and reinforce what is happening in many states and across the health care industry. If Congress withholds funding, this will not be possible.

Virtually everyone agrees that fundamental change is needed. But changing our enormously complicated and exceptionally fragmented health care system has proven to be a monumental and elusive challenge. Regardless of our political differences or any future Supreme Court decision, the ACA offers our nation a truly extraordinary and historic opportunity to make our country better.

Real and lasting change, though, will take time, resources and a commitment to do the hard work necessary to build a more effective health care system that is truly accessible and affordable for all Americans.

Wright is a professor of health policy and management and director of the Center for Health Policy in the Department of Public Health at the Indiana University School of Medicine.